Which term best describes the level of energy carried by a sound wave?

Which term best describes the level of energy carried by a sound wave?

• A. Pitch
• B. Loudness
• C. Quality
• D. Intensity

Answer: (D)

Energy carried by a sound wave is described by its intensity—the amount of power transmitted per unit area in the medium. Intensity rises with the amplitude of the pressure fluctuations, and for a given medium it’s proportional to the square of that amplitude, so larger swings move more energy. Pitch, determined by frequency, affects how high or low a note sounds but not how much energy is flowing. Loudness is our perception of how strong the sound seems, which depends on intensity but is not a direct measurement of energy itself. Quality (timbre) describes the tone color from the waveform’s shape and harmonic content, not the overall energy level. So the term that best describes the energy level carried by a sound wave is intensity.

Energy carried by a sound wave is described by its intensity—the amount of power transmitted per unit area in the medium. Intensity rises with the amplitude of the pressure fluctuations, and for a given medium it’s proportional to the square of that amplitude, so larger swings move more energy. Pitch, determined by frequency, affects how high or low a note sounds but not how much energy is flowing. Loudness is our perception of how strong the sound seems, which depends on intensity but is not a direct measurement of energy itself. Quality (timbre) describes the tone color from the waveform’s shape and harmonic content, not the overall energy level. So the term that best describes the energy level carried by a sound wave is intensity.